18966218 has 24 divisors (see below), whose sum is σ = 30426660. Its totient is φ = 8864640.

The previous prime is 18966217. The next prime is 18966221. The reversal of 18966218 is 81266981.

It can be written as a sum of positive squares in 2 ways, for example, as 17952169 + 1014049 = 4237^2 + 1007^2 .

It is not an unprimeable number, because it can be changed into a prime (18966217) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 78578 + ... + 78818.

Almost surely, 2^18966218 is an apocalyptic number.

18966218 is a deficient number, since it is larger than the sum of its proper divisors (11460442).

18966218 is a wasteful number, since it uses less digits than its factorization.

18966218 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 390 (or 371 counting only the distinct ones).

The product of its digits is 41472, while the sum is 41.

The square root of 18966218 is about 4355.0221583822. The cubic root of 18966218 is about 266.6819237798.

The spelling of 18966218 in words is "eighteen million, nine hundred sixty-six thousand, two hundred eighteen".